Perhaps you should try some spelling variations:
petruoov » petrov (Expand Search), peteruoov (Expand Search), petriuoov (Expand Search), petruuoov (Expand Search)
peterui » peterdi (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search)
petroui » peteroui (Expand Search), petrioui (Expand Search), petruoui (Expand Search)
petrioui » peterioui (Expand Search), petriioui (Expand Search), petruioui (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (Expand Search)

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: fop ((petruoov OR petruov) OR ((petroi OR (peterui OR (petroui OR petrioui))) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruoov OR petruov) OR ((petroi OR (peterui OR (petroui OR petrioui))) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruoov OR petruov) OR ((petroi OR (peterui OR (petroui OR petrioui))) OR petr)) o.s.*.